MMC SD fs boot partition config coding style and proper description

CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION ought to be called
CONFIG_SYS_MMCSD_FS_BOOT_PARTITION to keep it consistent with other config
options such as: CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR.

In addition, it is not related to raw mode booting but to fs mode instead.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/include/configs/sama5d3xek.h b/include/configs/sama5d3xek.h
index dfbf3cb..f2849d7 100644
--- a/include/configs/sama5d3xek.h
+++ b/include/configs/sama5d3xek.h
@@ -276,7 +276,7 @@
 #define CONFIG_SPL_MMC_SUPPORT
 #define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS	0x400
 #define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 0x200
-#define CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION	1
+#define CONFIG_SYS_MMCSD_FS_BOOT_PARTITION	1
 #define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME	"u-boot.img"
 #define CONFIG_SPL_FAT_SUPPORT
 #define CONFIG_SPL_LIBDISK_SUPPORT